Dragging front calipers 2012 Yukon with 6.2

[carlos h]

Have a buddy with a 2012 Yukon with 6.2 that has intermittent dragging front brakes that has no rhyme or reason to when they drag. It appears that when he bought the truck used last March that it had the issue as he had brand new brake setup up front and now he knows why.

He has replaced the brake lines in case they were collapsing.

I did a search and only came up with ensuring the brake slides are clean and unobstructed.

Thoughts and ideas?

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[gooffeyguy]

Also make sure the pins are lubed and the caliper can slide freely on the pins

2001 Yukon SLT
2012 Yukon XL Denali
2011 Yukon Denali RIP 5/20/18

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[carlos h]

Ok, will do that first, thanks

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[carlos h]

Just did a followup. New slides were installed and all pins slides allow calipers to move as designex

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[gooffeyguy]

Besides a bad caliper, maybe air in it or contaminated fluid? Has the fluid been changed and when was the system bled last?

2001 Yukon SLT
2012 Yukon XL Denali
2011 Yukon Denali RIP 5/20/18

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[carlos h]

He has had fluid flused twice in the last 3 months. You think the probability is high for 2 stuck calipers?

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[dnt1010]

Master Cylinder is suspect if BOTH calipers are not releasing at the SAME time.

 

[carlos h]

Update, sometimes both, sometimes just one. Leaning toward check valve in master cyl?

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[Doubeleive]

Update, sometimes both, sometimes just one. Leaning toward check valve in master cyl?

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pretty sure the proportioning valve only splits the pressure between front & rear and if it was stuck the brake light would be on or a check brake message would be present.

 

[carlos h]

Ok, thanks

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